The invention pertains to using an iron generating heat and steam for tasks such as pressing sheet material such as fabric. Such irons have been used for a long time. A typical contemporary iron has an electric heating element and often, although not always, a water container and the ability to generate steam issuing from a pattern of holes in its sole plate. The sole plate typically is metal and often is coated with a slippery material such as Teflon or other PTFE substances.
There have been proposals for supplying such irons with a removable sole plate cover made of a slippery and heat resistant material that is considerably thicker than the typical fixed coating of the same or similar material on the sole plate of some irons. One proposal is discussed in U.S. Pat. No. 5,664,349 and others are discussed in references cited on the face of the patent and in its columns 2-4. It is believed that covers similar to that discussed in the patent are, and have been for some time, on sale in this country. The patent states that the removable cover is flat, with no protuberances, and is "adapted to provide direct, continuous, unbroken contact with the sole plate of the iron and completely thereover . . . excepting said steam vent holes of said cover and any steam vent holes of the sole plate." One difficulty with such covers is that because of the wide variety of patterns of steam holes in the sole plate of irons, it cannot be expected that the steam holes in the removable cover will match those in the sole plate of the iron. As a result of a mismatch, there can be inefficient delivery of steam to the fabric or other material being ironed. An earlier U.S. Pat. No. 4,209,921 proposes a removable Teflon cover that would have collars at the steam vent holes and ridges elsewhere to thereby vertically space the major upper surface of the cover from the sole plate of the iron. However, if those collars and ridges are not formed from a flat sheet of PTFE by a simple process but require specially molded material or material formed from a flat sheet through an expensive treatment, they can add unreasonable expense to the product.
In order to provide a good balance between effectiveness and cost, the removable sole plate cover disclosed herein uses a flat sheet of a material such as PTFE (Teflon) but spaces it from the sole plate of the iron by punching and stretching the steam holes in the cover in a process that created protuberances at the upper edges of the holes. The inventor has discovered that the protuberances that this punching and stretching creates are sufficient to maintain enough of that major surface spaced from the sole plate of the iron while pressing is carried out and is further sufficient to facilitate efficient delivery of steam to the material being ironed even when there is poor vertical alignment between steam holes in the sole plate and in the removable cover. In addition, the inventor has discovered a particularly effective and inexpensive way to form the sheet material of the cover into a pocket matching the tip of the iron, and a particularly effective and flexible way to removably attach the cover to the iron and maintain it in place during ironing.